Original paper - Diggle, et. al. (2007). Spatial modelling and prediction of Loa loa risk: decision making under uncertainty. Annals of Tropical Medicine and Parasitology, 101, 499-509.
no_exam and no_inf - Collected between 1991 and 2001 by NGOs (original paper mentions 168 villages and 21,938 observations)
elev - USGS gtopo30 (1km resolution)
mean9901, max9901, min9901, stdev9901 - aggregated NDVI data from 1999 to 2001 from the Flemish Institute for Technological Research (1 km resolution)